Thumb2 Backend: Update Code objects with mode, separate Assembler methods for Thumb2

src/objects.h

Index: src/objects.h
diff --git a/src/objects.h b/src/objects.h
index d3593b6edce9003f38fbceee97d72c503bb47368..51c37082a78c11db58bc74e7eef68b03a1bced4a 100644
--- a/src/objects.h
+++ b/src/objects.h
@@ -4929,6 +4929,8 @@ class Code: public HeapObject {
   inline bool is_pregenerated();
   inline void set_is_pregenerated(bool value);
 
+  inline bool is_thumb_mode();
+
   // [optimizable]: For FUNCTION kind, tells if it is optimizable.
   inline bool optimizable();
   inline void set_optimizable(bool value);
@@ -5046,6 +5048,8 @@ class Code: public HeapObject {
     return ExtraICStateStubHolder::encode(stub_holder);
   }
 
+  static inline Flags SetThumbModeInFlags(Flags flag);
+
   // Flags operations.
   static inline Flags ComputeFlags(
       Kind kind,
@@ -5053,7 +5057,8 @@ class Code: public HeapObject {
       ExtraICState extra_ic_state = kNoExtraICState,
       StubType type = NORMAL,
       int argc = -1,
-      InlineCacheHolderFlag holder = OWN_MAP);
+      InlineCacheHolderFlag holder = OWN_MAP,
+      bool thumb_mode = false);
 
   static inline Flags ComputeMonomorphicFlags(
       Kind kind,
@@ -5216,9 +5221,10 @@ class Code: public HeapObject {
   class CacheHolderField: public BitField<InlineCacheHolderFlag, 6, 1> {};
   class KindField: public BitField<Kind, 7, 4> {};
   class IsPregeneratedField: public BitField<bool, 11, 1> {};
-  class ExtraICStateField: public BitField<ExtraICState, 12, 5> {};
-  class ExtendedExtraICStateField: public BitField<ExtraICState, 12,
-      PlatformSmiTagging::kSmiValueSize - 12 + 1> {};  // NOLINT
+  class IsThumbModeField: public BitField<bool, 12, 1> {};
+  class ExtraICStateField: public BitField<ExtraICState, 13, 5> {};
+  class ExtendedExtraICStateField: public BitField<ExtraICState, 13,
+      PlatformSmiTagging::kSmiValueSize - 13 + 1> {};  // NOLINT
   STATIC_ASSERT(ExtraICStateField::kShift == ExtendedExtraICStateField::kShift);
 
   // KindSpecificFlags1 layout (STUB and OPTIMIZED_FUNCTION)
@@ -5274,7 +5280,7 @@ class Code: public HeapObject {
       kIsCrankshaftedBit + 1 + 29, 1> {};  // NOLINT
 
   // Signed field cannot be encoded using the BitField class.
-  static const int kArgumentsCountShift = 17;
+  static const int kArgumentsCountShift = 18;
   static const int kArgumentsCountMask = ~((1 << kArgumentsCountShift) - 1);
   static const int kArgumentsBits =
       PlatformSmiTagging::kSmiValueSize - Code::kArgumentsCountShift + 1;